Signal shift device



FIG. 1 is a front, top, right side perspective view;

FIG. 2 is a front elevation view;

FIG. 3 is a rear elevation view;

FIG. 4 is a left side elevation view;

FIG. 5 is a right side elevation view;

FIG. 6 is a top plane view;

FIG. 7 is a bottom plane view; and,

FIG. 8 is a front, top, right alternate side perspective view of the sign on a trailer. 

The ornamental design for signal shift device, as shown and described. 